<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>回调地狱</title>
    </head>
    <body>
    <script>
        //回调地狱 当回调函数互相嵌套，嵌套层级过多，导致代码维护性变差，这种解构我们叫做回调地狱
        function ajax(url,sucesscb,errorcb){
            setTimeout(()=>{
                sucesscb('1111')
            },1000)
        }

        //回调地狱
        ajax('/aaa',(data)=>{
            console.log(data)
            ajax('/bbb',(data)=>{
                console.log(data)
                ajax('/ccc',()=>{

                },()=>{})
            },()=>{})
        },()=>{})
    </script>
    </body>
</html>